Lightning-arrester.



E. B. CRAFT.

LIGHTNING ARRESTER.

APPLIOATION FILED MAR. 1, 191a.

Patented June 30, 19M

Ill l I I IIHI I IIHHHH I HH" i m W W W MW E CRAFT, OF HACKENSACK, NEW'J'ERSEY, ASSIGNGR'TO"WESTERN ELECTBIGi EDWARD B.- p

" COHPKNY, or nnwyorm, n. Y., A: conroaarron or ILLINOIS.

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1,101, 7281. Specification of'Letters- Patent. P t t d June 30. m -4; Application filed March 1, 913. eria1No.751,568.

T aZZ h ii concemj copper, brass or other suitable metal. The

Be'it'known that I, EDWARD B. CRAFT, a citizen of the United States, residing at Hackensack, in the county of Bergen and State of New Jersey, have invented certain new and useful Improvements in Lightning- Arresters, of which the following is a. full, clear, concise, and exact description.

My invention relates to lightning arrest: ers, and is particularly adapted for embodiment in arresters of the vacuum type.

The general object of my invention is to provide a new and improved arrester which is simple in construction, easy to manufacture, and reliable and eflicient in operation.

Although not limited'to' use 'in connection with telephone and telegraph circuits, it is particularly satisfactoryin that service in which low cost of maintenance and reliability of operation are important factors.

My invention will be readily understood from the following description takenin connection with the accompanying drawing in which a lightning arrester embodying said invention is described and illustrated.

The drawing is an elevation of the arrester, the container, base and electrode structure being shown in cross-section.

The evacuated container 5, within which the electrodes of the arrester are mounted, may be of glass formed and evacuated in the same well-known manner as are incandescent lamp bulbs. The point 6 indicates the place at which the bulb or container is sealed after evacuation. Within the container 5 is an electrode support which has a hollow stem portion 7 resembling the Wellknown form 'of stem used in the filament support of an incandescent lamp, said stem having a flared bottom 8, the edges of which are welded at 9 to the edges of the container 5. Extending inwardly from, the stem 7 is a solid or hollow rod 11, preferably of glass, upon which the electrodes of the arrester are supported. The stem 7 and rod 11 comprise the electrode support.

As shown in the drawing, the rod 11 is provided with a boss 12 upon which rests the inner cylindrical electrode 14 which is hollow and surrounds the rod 11. The outer electrode 15 is also cylindrical, and has a contracted portion 16, as shown in the drawing. Preferably both electrodes are made of aluminum, although they may be made 'of end: of the rod 11 as shown at 21. understood, of course," that suchassembling is done before the electrode support is placed outer cylindrical electrode 15 is held in proper relation to the inner electrode 14 by washers 18 and 19 of insulating material such as lavite. These washers or disks '18and l9 areperforated as shown at 20 in glermit the ready evacuation of the,

order to space wi in. theouter electrode 15, and to 'afiiord vents for the relief of any pressure created in said spacev by an excessive arc.

the outside electro e515, then applying the washer'18, and finally by spinning over-the It is within the container 5.

Electrical connection with'the electrodes 14 and 15 .is obtained through leading-in wires 27 and 28 which pass through the top of the stem 7 and are sealed therein. The necessary air-tight seal may be obtained in the well-known manner by interposing pieces of platinum 25' in said leading-in Wires within the glass seal. The inner ends of the leading-in wires 27 and 28 are connected to the electrodes 14 and 15 in any suitable manner as by welding orsoldering or by the screws 30 as shown. The'outer ends of said leading-in wires are connected to any suitable form of base which may be cemented to the outside of the container 5. The base shown in the drawing resembles an incandescent lamp base of well-known form, but instead of being threadedon its' ton 35 is cemented to theend of the container 5 to .which the electrode support has been welded, The leading-in wire 27 is brought out through a hole in thebutton 35 and is soldered to said button as shown at 36. The other leading-in wire 28. is brought out between the container 5 and the shell 32 and is;D sozldered to the edge of the shell as shown a 3 From the foregoing description, it will be apparent that the outer surface of the inner electrode 14: and the inner surface of the contracted portion 16 of the outer electrode can be so proportioned as to diameter that a discharge through the arrester will take place at a 'ven voltage; and that the elecv trodes can" e easily assembled so that their cooperating arcing surfaces are in proper relation to one another. Itwill also be evident that the arcing will be confined to the area between the contracted portion 16 of the outer electrode and the surface of the inner electrode 14, thereby keeping the are away from the washers 18 and 19. This arrangement of electrodes also efiectively prevents the are from reaching the walls of the evacuated container 5, which being preferably of glass would be damaged by such are. The structure shown, therefore, permits repeated discharges through the arrester without injury to any parts adjacent the arcing surfaces of the electrodes.

I claim:

A lightning arrest-er comprising an evacuated glass container, a glass electrode suport having a stem portion welded into and orming part of the wall of said container and having a rod portion extending from said stem portion into the container, a'hollow cylindrical electrode surroundin and supported by the rod portion of sai support, another hollow cylindrical electrode surrounding said first-mentioned electrode, insulating disks supporting said Outer cylindrical electrode in operative relation to said inner cylindrical electrode, leading-in wires sealed into and passing through said support and connected to said electrodes, and a base secured to the outside of said container and 7 connected to said leading-in wires whereby electrical connection may be made with said arrester.

In witness whereof, I hereunto subscribe my name this 26th day of February A. D.,

EDWARD B. CRAFT.

Witnesses:

WALTER F. HorrMAN, O. D. M. Goran. 

